A Texan who began training for the Navy SEALS at 14, Marcus Luttrell has become a media personality and supporter of conservative political causes. He spoke in support of Donald Trump at the Republican National Convention Monday night.

Luttrell’s story as the only soldier to emerge alive from an extended 2005 battle with the Taliban in Afghanistan’s eastern mountains was popularized by the book Lone Survivor. In 2013, Mark Wahlberg played Luttrell in a movie of the same name that grossed $125 million. The real Luttrell appeared briefly in the movie. He also launched the Lone Survivor Foundation in 2010 to help wounded veterans heal and reintegrate into society.

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Since the movie’s commercial success, Luttrell has supported former Texas Gov. Rick Perry and Donald Trump in the 2016 presidential race. Last month, he said on Facebook that he spent Father’s Day with Trump and Perry in Texas. The Texan identifies as a member of self-created “Team Never Quit” and has built a social media following through his display of a tough, resilient persona.

Luttrell’s speech at the Republican National Convention comes during the first day’s “Make America Safe Again” theme. The day also focuses attention on the deaths of four Americans in Benghazi while Hillary Clinton was Secretary of State. Republicans have long said Clinton’s handling of the attack on the U.S. embassy in Benghazi shows she is unfit to be commander-in-chief. But a GOP House-led committee found no new wrongdoing by Clinton in a report released last month.